The Dynavap series is another killer vaporizer that doesn't need a battery!The on-demand conduction/convection heating is provided by a butane lighter, or a regular lighter, or a candle, burning stick, stove element etc!The units are absolutely tiny but provide an amazing vapour experience.The ever-popular Dynavap M has now been updated for 2018 to further increase the performance of this amazing ultra portable, ultra affordable vaporizer!